Different types of breast pumps exist to aid in extracting milk from the breasts of lactating women. Breast pumps may be manual devices powered by hand or foot movements, or powered electrical devices where a breast shield via tubing is coupled to a pump motor powered by mains electricity or batteries.
Most breast pumps allow direct collection of pumped breast milk into a container that can be used for storage and feeding. The plastic tubing and breast shield of a breast pump is commonly referred to as the collection system.
Different types of pump motors are used in breast pumps to create the suction such as piston pumps or rotary vane pumps. In order to avoid a free passage of air as well as to prevent any contamination or overflow into pump motor, a bacteria filter, a diaphragm or some kind of barrier must be inserted in the tubing between the breast shield and the connection to the pump motor. In this design, the suction of the pump motor lifts the diaphragm to create a vacuum within the collection system to extract milk. However the diaphragm or filter causes a considerable reduction in the suction obtainable at the breast compared to the suction at the exit of the pump motor. Also, the diaphragm or filter tends to deform differently from suction cycle to suction cycle which then lead to changes in the obtained suction and difficulties in controlling the suction level.
Another drawback of the known apparatus is the level of noise emitted by the pump motor which decreases the user comfort.